1. Field of the Invention
The present invention relates to a stator of a rotary electric machine to be mounted in a vehicle such as a passenger car or a truck and a method of manufacturing such a stator.
2. Description of the Related Art
As the output power of the vehicle generators has been increasing in order to operate various vehicle safety devices. It is well known that the output power of a vehicle ac generator can be increased if the space factor of a stator winding to stator core's slots is increased, which reduces the resistance of the stator winding. The space factor can be increased if the conductors or wires of the stator winding inserted in the slots are snugly fitted to the slots.
For example, Japanese Patents P3196738, P3104700 and Japanese Patent Application Publication P2001-197709, or their corresponding US Patent Application Publication US2002/0053126A1, U.S. Pat. No. 6,403,921B1 and US Patent Application Publication 2001/0007169A1, disclose methods of manufacturing a stator.
FIG. 14 shows one of the methods disclosed in the above-stated publications. As shown in FIG. 14, a plurality of U-shaped conductor segments 404 is inserted into slots of a stator core 400, and the conductor segments 404 are bent to incline in the circumferential direction while connection ends 406 of the conductor segments 404 are clamped. Thereafter, the connection ends 406 are welded together by an arc welder to form a stator winding.
When a stator is manufactured by the above-described method, the connection ends 406 have to have a certain length of axially extending straight portion, which increases useless axial size of the stator.